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  <title>Gets the number of rows in a result</title>

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 <div class="refnamediv">
  <h1 class="refname">mysqli_result::$num_rows</h1>
  <h1 class="refname">mysqli_num_rows</h1>
  <p class="verinfo">(PHP 5)</p><p class="refpurpose"><span class="refname">mysqli_result::$num_rows</span> -- <span class="refname">mysqli_num_rows</span> &mdash; <span class="dc-title">Gets the number of rows in a result</span></p>

 </div>

 <div class="refsect1 description" id="refsect1-mysqli-result.num-rows-description">
  <h3 class="title">说明</h3>
  <p class="para">面向对象风格</p>
  <div class="fieldsynopsis"><span class="type">int</span> <var class="varname"><a href="mysqli-result.num-rows.html">$mysqli_result-&gt;num_rows</a></var>;</div>

  <p class="para">过程化风格</p>
  <div class="methodsynopsis dc-description">
   <span class="type">int</span> <span class="methodname"><strong>mysqli_num_rows</strong></span>
    ( <span class="methodparam"><span class="type"><a href="class.mysqli-result.html" class="type mysqli_result">mysqli_result</a></span> <code class="parameter">$result</code></span>
   )</div>

  <p class="para rdfs-comment">
   Returns the number of rows in the result set.
  </p>
  <p class="para">
   The behaviour of <span class="function"><strong>mysqli_num_rows()</strong></span> depends on whether 
   buffered or unbuffered result sets are being used.
   For unbuffered result sets, <span class="function"><strong>mysqli_num_rows()</strong></span>
   will not return the correct number of rows until all the rows in the result
   have been retrieved.
  </p>
 </div>


 <div class="refsect1 parameters" id="refsect1-mysqli-result.num-rows-parameters">
  <h3 class="title">参数</h3>
  <p class="para">
   <dl>

    <dt>
<em><code class="parameter">
result</code></em></dt>
<dd>
<p class="para">仅以过程化样式：由
<span class="function"><a href="mysqli.query.html" class="function">mysqli_query()</a></span>，<span class="function"><a href="mysqli.store-result.html" class="function">mysqli_store_result()</a></span> 或
<span class="function"><a href="mysqli.use-result.html" class="function">mysqli_use_result()</a></span>返回的结果集标识。</p></dd>

   </dl>

  </p>
 </div>


 <div class="refsect1 returnvalues" id="refsect1-mysqli-result.num-rows-returnvalues">
  <h3 class="title">返回值</h3>
  <p class="para">
   Returns number of rows in the result set.
  </p>
  <blockquote class="note"><p><strong class="note">Note</strong>: 
   <p class="para">
    If the number of rows is greater than <strong><code>PHP_INT_MAX</code></strong>, the number
    will be returned as a string.
   </p>
  </p></blockquote>
 </div>


 <div class="refsect1 examples" id="refsect1-mysqli-result.num-rows-examples">
  <h3 class="title">范例</h3>
  <div class="example" id="example-1718">
   <p><strong>Example #1 面向对象风格</strong></p>
   <div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB">&lt;?php<br />$mysqli&nbsp;</span><span style="color: #007700">=&nbsp;new&nbsp;</span><span style="color: #0000BB">mysqli</span><span style="color: #007700">(</span><span style="color: #DD0000">"localhost"</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"my_user"</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"my_password"</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"world"</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">/*&nbsp;check&nbsp;connection&nbsp;*/<br /></span><span style="color: #007700">if&nbsp;(</span><span style="color: #0000BB">mysqli_connect_errno</span><span style="color: #007700">())&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">printf</span><span style="color: #007700">(</span><span style="color: #DD0000">"Connect&nbsp;failed:&nbsp;%s\n"</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">mysqli_connect_error</span><span style="color: #007700">());<br />&nbsp;&nbsp;&nbsp;&nbsp;exit();<br />}<br /><br />if&nbsp;(</span><span style="color: #0000BB">$result&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">$mysqli</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">query</span><span style="color: #007700">(</span><span style="color: #DD0000">"SELECT&nbsp;Code,&nbsp;Name&nbsp;FROM&nbsp;Country&nbsp;ORDER&nbsp;BY&nbsp;Name"</span><span style="color: #007700">))&nbsp;{<br /><br />&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #FF8000">/*&nbsp;determine&nbsp;number&nbsp;of&nbsp;rows&nbsp;result&nbsp;set&nbsp;*/<br />&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">$row_cnt&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">$result</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">num_rows</span><span style="color: #007700">;<br /><br />&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">printf</span><span style="color: #007700">(</span><span style="color: #DD0000">"Result&nbsp;set&nbsp;has&nbsp;%d&nbsp;rows.\n"</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$row_cnt</span><span style="color: #007700">);<br /><br />&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #FF8000">/*&nbsp;close&nbsp;result&nbsp;set&nbsp;*/<br />&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">$result</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">close</span><span style="color: #007700">();<br />}<br /><br /></span><span style="color: #FF8000">/*&nbsp;close&nbsp;connection&nbsp;*/<br /></span><span style="color: #0000BB">$mysqli</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">close</span><span style="color: #007700">();<br /></span><span style="color: #0000BB">?&gt;</span>
</span>
</code></div>
   </div>

  </div>
  <div class="example" id="example-1719">
   <p><strong>Example #2 过程化风格</strong></p>
   <div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB">&lt;?php<br />$link&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">mysqli_connect</span><span style="color: #007700">(</span><span style="color: #DD0000">"localhost"</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"my_user"</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"my_password"</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"world"</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">/*&nbsp;check&nbsp;connection&nbsp;*/<br /></span><span style="color: #007700">if&nbsp;(</span><span style="color: #0000BB">mysqli_connect_errno</span><span style="color: #007700">())&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">printf</span><span style="color: #007700">(</span><span style="color: #DD0000">"Connect&nbsp;failed:&nbsp;%s\n"</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">mysqli_connect_error</span><span style="color: #007700">());<br />&nbsp;&nbsp;&nbsp;&nbsp;exit();<br />}<br /><br />if&nbsp;(</span><span style="color: #0000BB">$result&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">mysqli_query</span><span style="color: #007700">(</span><span style="color: #0000BB">$link</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"SELECT&nbsp;Code,&nbsp;Name&nbsp;FROM&nbsp;Country&nbsp;ORDER&nbsp;BY&nbsp;Name"</span><span style="color: #007700">))&nbsp;{<br /><br />&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #FF8000">/*&nbsp;determine&nbsp;number&nbsp;of&nbsp;rows&nbsp;result&nbsp;set&nbsp;*/<br />&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">$row_cnt&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">mysqli_num_rows</span><span style="color: #007700">(</span><span style="color: #0000BB">$result</span><span style="color: #007700">);<br /><br />&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">printf</span><span style="color: #007700">(</span><span style="color: #DD0000">"Result&nbsp;set&nbsp;has&nbsp;%d&nbsp;rows.\n"</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$row_cnt</span><span style="color: #007700">);<br /><br />&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #FF8000">/*&nbsp;close&nbsp;result&nbsp;set&nbsp;*/<br />&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">mysqli_free_result</span><span style="color: #007700">(</span><span style="color: #0000BB">$result</span><span style="color: #007700">);<br />}<br /><br /></span><span style="color: #FF8000">/*&nbsp;close&nbsp;connection&nbsp;*/<br /></span><span style="color: #0000BB">mysqli_close</span><span style="color: #007700">(</span><span style="color: #0000BB">$link</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">?&gt;</span>
</span>
</code></div>
   </div>

   <div class="example-contents"><p>以上例程会输出：</p></div>
   <div class="example-contents screen">
<div class="cdata"><pre>
Result set has 239 rows.
</pre></div>
   </div>
  </div>
 </div>


 <div class="refsect1 seealso" id="refsect1-mysqli-result.num-rows-seealso">
  <h3 class="title">参见</h3>
  <p class="para">
   <ul class="simplelist">
    <li class="member"><span class="function"><a href="mysqli.affected-rows.html" class="function" rel="rdfs-seeAlso">mysqli_affected_rows()</a> - Gets the number of affected rows in a previous MySQL operation</span></li>
    <li class="member"><span class="function"><a href="mysqli.store-result.html" class="function" rel="rdfs-seeAlso">mysqli_store_result()</a> - Transfers a result set from the last query</span></li>
    <li class="member"><span class="function"><a href="mysqli.use-result.html" class="function" rel="rdfs-seeAlso">mysqli_use_result()</a> - Initiate a result set retrieval</span></li>
    <li class="member"><span class="function"><a href="mysqli.query.html" class="function" rel="rdfs-seeAlso">mysqli_query()</a> - 对数据库执行一次查询</span></li>
   </ul>
  </p>
 </div>


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